Hot Topics:

CU-Boulder research unearths ancient high-Arctic bird

By Carah Wertheimer

For the Camera

Posted:
03/12/2016 01:17:28 PM MST

Updated:
03/12/2016 05:26:47 PM MST

University of Colorado researcher Jaelyn Eberle has helped establish that Gastornis, a bird six feet tall, several hundred pounds and flightless, which was common in the Rocky Mountain west, also lived in the high Arctic during the Eocene era. (Marlin Peterson / Courtesy illustration)

Fifty million years ago, Gastornis, a 6-foot tall flightless bird inhabiting what is now Colorado and Wyoming, also lived in the Canadian high Arctic, according to Jaelyn Eberle, associate professor of geological sciences at the University of Colorado.

In Scientific Reports, Eberle and lead author Thomas Stidham, avian paleontology professor at the Chinese Academy of Sciences, "describe" (the scientific examination and confirmation of a specimen's identity) a Gastornis and the only other bird fossil from the early Eocene high arctic, Presbyornis.

Both fossils were first discovered on Ellesmere Island in the 1970s by paleontologists on pioneering expeditions, aided by new maps from the Geological Survey of Canada.

Early Eocene Ellesmere was a cypress swamp, more like New Orleans than Nome. Primates, turtles, alligators, and mammals resembling hippos and rhinos carried about in a temperate rainforest. As today, however, the island was completely dark three months a year.

Denver resident Mac West, one of the Arctic explorers, said they would typically skim off the types of fossils they study, and release the rest. There are likely thousands of Arctic fossils sitting in Canadian storage, between his expeditions and many subsequent trips by others, he said.

Eberle, a mammalian paleontologist, got involved after Stidham crossed paths with the Presbyornis fossil during a research trip to the Carnegie Museum in Pittsburgh. The fossil was sent there on its way back to Canada.

Advertisement

"It was just good timing. Otherwise, I don't know if anyone would have known that the specimens were available again for people to examine," Stidham said.

In the process of describing, he reached out to Eberle for her Arctic geology expertise. Their first paper, on Presbyornis, was returned by the publisher, who insisted they also describe Gastornis.

Eberle located the Gastornis fossil in storage at the Canadian Museum of Nature. "The first email I got they said 'Great! Yeah we have it catalogued — no problem.'" Then the next email arrived.

"We thought that we might not be able to include it, and it's that bird that seems to have grabbed the public's interest the most," Stidham said.

Missing specimens are not at all unusual.

"When you have hundreds of thousands, or millions, of specimens, one getting put back in the wrong spot happens," he said.

Eberle, also curator of fossil vertebrates at the CU Museum of Natural History, said, "They worked pretty hard, I think. They totally went to bat and found it," she said.

Although Stidham is the avian paleontologist and Eberle's background is mammalian, shipping a small 50 million year-old fossil to China presented risk.

The plan was to send it to Eberle, who would then share high-resolution images with Stidham using the CU Museum's entomology imaging lab.

Eberle compared the Canadian specimen against CU Museum specimens from Garfield County, Colorado and Wyoming's Big Horn and Powder River basins. Stidham compared the Canadian images with European Gastornis specimens on hand in China. They concluded that the toe bone belonged to Gastornis.

Eberle, also curator of fossil vertebrates at the CU Museum of Natural History, usually works with mammal fossils, which are more common and generally better preserved. Bird fossils from the arctic are even more unusual, she said.

Due to climate change, Stidham said, scientists are observing changes in the distribution of birds.

"We can predict that with ongoing global warming, that birds will continue to move north and may even become Arctic residents someday, possibly even emigrating to other continents through the Arctic just like we see in the fossil record."

Knights pick up first playoff win since '14BOULDER — This year's Fairview boys basketball team sure is full of surprises.
After losing five of their first eight games, the Knights rebounded to finish the regular season on a 13-2 run and found a way to win the Front Range League regular season championship. Full Story

The Boulder alt-country band gives its EPs names such as Death and Resurrection, and its songs bear the mark of hard truths and sin. But the punk energy behind the playing, and the sense that it's all in good fun, make it OK to dance to a song like "Death." Full Story